I wanted to use the github API to get a list of those who watch the project, and then send an email to those people. Unfortunately the API does not let you query that yet. Instead, my script lets you specify the recipients manually. Alternatively, a simple mailing list implementation is provided so people can sign up for the post-receive emails through a webpage instead.

The only downside is that the JSON github provides does not include information about how many lines were modified, just files. In this respect, Andy Parkin’s post-receive script produces slightly more informative e-mails (but of course it doesn’t work with github).